Operation of devices that send or receive signals is generally prohibited on board commercial aircrafts while in flight, due to the potential impact on aircraft avionics and the potential for interference with ground cell networks.
Flight mode is a setting available on many electronic devices that, when engaged, suspends many of the device's signal transmitting functions, thereby disabling, e.g. a mobile phone's capacity to place or receive calls or text messages while still permitting use of other functions that do not require signal transmission; e.g., games, built-in camera, MP3 player.
Flight mode permits the user to operate the device while on board a commercial aircraft while in flight.
Other names include airplane mode, aeroplane mode, offline mode, and standalone mode.
Head-worn devices with transceivers for wireless communication with other devices and with other functions that do not require wireless communication are well-known, e.g. hearing aids.